looks like you also got that Aug an P90 achievement to.
I hope the do a roll back I mean this will make me annoyed that I have achievement I didn't earn.
Knife Kills:
-1,073,741,820 rofl
It must be a recent problem as mine are fine... http://steamcommunity.com/id/IBIS/st...subtab=summary
mine haven't been effected, maybe you do hack...